Triagem de marcadores na seleção genômica ampla

• Autor(a) principal: Marinho, Caillet Dornelles
• Data de Publicação: 2014
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1398
• topic: Eucalipto - Melhoramento genético; Seleção genômica; Eucalyptus - Breeding; Genomic selection; CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::SILVICULTURA::GENETICA E MELHORAMENTO FLORESTAL

A genome wide selection (GWS) has been proposed to increase the efficiency of breeding programs and to optimize the selection process using pre-estimated information from hundreds or thousands molecular markers. The most suitable and usedfor this purpose are DArTs and SNPs markers. However, despite the advances in molecular biology and related reduction in the price of obtaining markers for genotyping many individuals with high density of markers, it may not be economically feasible in some breeding programs yet, depending on the species. Given the above, the objectives of this work were:i) screening markers for genomic selection in eucalypt selection by the effect of markers and by linkage disequilibrium (LD) with verification of predictive capacity after number of markers reduction; ii) verification of the expected genetic gain based on phenotypic selection and use of GWS, with and without markers selection; iii ) to compare the use of DArTand SNP markers in GWS in the same population of Eucalyptus; iv ) proposing new validation for RR-BLUP-B method proposed by Resende et al . (2010). Results demonstrate that the selection of markers can maintain the predictive ability of the methods GWS very close to those obtained using all markers. The genetic gain per unit of time, regardless of the method used, were superior to the traditional selection and can be maintained using selection markers. Moreover, in this study the reduction approach via linkage disequilibrium (PTMOD) was higher than RR-BLUP-B (effect of markers), but with a smaller reduction in the number of selected SNPs. For the population of eucalyptus and variables used in this study, DArTsmarkers with lower density showed better predictions in GWS regarding the use of SNP markers with higher density. The RR-BLUP-B modified overestimated the predictive ability compared to the original RR-BLUP-B method. Soitis recommended an independent validation as the best form of validation.